Ion exchange membranes are a type of polymer material used as solid electrolytes in electrolysis and electrochemical applications, such as chemical production and water treatment. IDTechEx's report, "Ion Exchange Membranes 2025-2035: Technologies, Markets, Forecasts", covers the latest developments in membrane manufacturing and application sectors.
The porous structures of ion exchange membranes with ionically charged chemical side chains allow them to selectively transport specific ions while blocking others. Cation exchange membranes allow for the transportation of small cations such protons, lithium, and sodium, while anion exchange membranes have a positively charged internal structure and allow for the transportation of anions like chloride and hydroxide.
Technologies of today and key applications
Perfluorosulfonic acid based (PFSA) membranes are the most mature and dominant membrane technology today and are largely used as cation or proton exchange membranes. The primary strengths of PFSAs are their high chemical resilience and mechanical strength, allowing the membrane to be resistant to degradation.
Ion exchange membranes can also consist of hydrocarbon-based materials, such as polyaromatics. Hydrocarbon membranes can function as cation, proton, or anion exchange membranes based on the given side chain functionality and charge. They have highly tuneable ionomer chemistry, as well as having the potential to be cheaper than PFSAs and PFAS-free, making them a desirable option. In 2025 however, PFSA membranes represent the majority of annual ion exchange membrane demand, with hydrocarbon membranes only making up a small amount of the market.
Ion exchange membranes are established in chemical production and processing, and water treatment markets, with high maturity. In chemical production, they are used within the chloralkali process and in salt splitting electrolysis circuits. They are also used for chemical purification and recovery. In water treatment, membranes are used in wastewater treatment, drinking water production, and ultra-pure water generation.
Key membrane development trends
Increasing the ionic conductivity of membranes improves energy efficiency and power density in applications such as fuel cells and electrolyzer systems. Reducing film thickness or modifying underlying ionomer chemistry are two ways to achieve this, alongside doping methods with conductive additives. A higher ion exchange capacity, determined by how many ions a membrane is capable of displacing, also ensures increased energy efficiency and power density, and can be achieved by increasing functional group loading within the membrane.
Another key performance attribute within ion exchange membranes is chemical stability which is necessary for increasing system lifetime and improving performance. Modifying the ionomer chemistry, such as by using more chemically inert chemistries such as perfluorinated groups and coating the membrane with catalysts are two ways to achieve this, explored in IDTechEx'slatest report. Mechanical and dimensional stability, on the other hand, is critical for increasing system lifetime and improving safety in integrated systems and can be imparted by reinforcing the membrane or increasing its thickness.
The development of membranes with specific qualities often requires a trade off when considering performance, safety, and durability. Safety and stability achieved with thicker membranes is likely to lead to a compromise in conductivity performance, and IDTechEx reports manufacturers having to balance these attributes to achieve a desired outcome.
Emerging applications within the market
The decarbonized energy and transport markets are two of the largest areas driving future investment and growth for ion exchange membranes. Hydrogen fuel cells, redox flow batteries, water electrolyzers, and carbon capture and utilization are the main emerging applications listed in IDTechEx's report.
As these emerging applications grow, ion exchange membranes are advancing to become increasingly specialized in order to meet demand. For more information and greater detail on manufacturing methods and material innovations, visit the report, "Ion Exchange Membranes 2025-2035: Technologies, Markets, Forecasts", and the wider portfolio of Advanced Materials & Critical Minerals Research Reports and Subscriptions.
